Method and apparatus for conditioning metal parts for lubrication



Jan. 20, 1970 T. N. STEPHENS 3,491,227

METHOD AND vAPPARATUS FOR CONDITIONING METAL PARTS FOR LUBRICATION Filed Aug. 5, 1966 I N VEN TOR.

' ATTORNEYS United States Patent 3,491,227 METHOD AND APPARATUS FOR CONDITIONING METAL PARTS FOR LUBRICATION Thomas N. Stephens, 4716 Irvington Blvd.,

Houston, Tex. 77022 Filed Aug. 3, 1966, Ser. No. 569,982 Int. Cl. F27d 11/00 US. Cl. 219-439 5 Claims ABSTRACT OF THE DISCLOSURE An apparatus for treating metal parts, the apparatus having a treatment vessel that includes a plurality of corners and which is surrounded by a second vessel in spaced relation thereto. Vertically disposed heating elements are positioned adjacent each corner of the treatment vessel between the treatment and second vessels and are regulated by a temperature control means. A heating liquid is provided in the space between the two vessels to transfer heat from the heating elements to the treatment vessel.

The present invention relates to apparatus used in metal treating processes and more particularly to a method and means used for the application of heat in and to said apparatus used to condition metal products for lubrication.

In the lubrication of metal parts, it is known in the art that a prior treatment of the part with a solution such as manganese phosphate under certain conditions will result in better lubrication of the part during its operation. This is due to the action of the manganese phosphate during the treatment which action etches the part and then deposits manganese phosphate crystals in the etched metal surface. These crystalline deposits or coatings attract the lubrication to the part so treated and cause the lubricant to adhere better and longer. The result is improved lubrication thus providing longer life for the treated part.

To achieve such a result, however, the treatment of the part must be performed under certain conditions. By way of example, in using a solution of manganese phosphate, the temperature of the treating solution must be maintained between 200-210 F., and the temperature must be uniform throughout the solution. Absent this, the treatment will be defective and uneven and may result in crystalline coatings of undesired thicknesses. This will, in turn, result in failures and shorter than normal life spans of the treated parts due to the improper adherence of 'the lubricant. An additional problem that arises from improper heating is that of the loss of the treating solution due to the boiling off or to the breaking down of the solution itself. Furthermore, an uneven application of heat to the treating vessel may result in hot spots in the vessel itself. The conditioning or treating substance is attracted to the hottest areas and, in the case of manganese phosphate for example, the manganese phosphate will flake out and result in sludging in the treating solution, with resultant deterioration of the solution and damage to the treating vessel.

The present invention seeks to overcome these disadvantages by providing novel treating apparatus wherein the treating solution is evenly heated throughout and wherein no hot spots are created in the equipment. This is achieved by providing a novel arrangement, partially comprised of an outer vessel concentrically disposed in spaced relation to the treating vessel. In the presently preferred embodiment, both vessels are four-cornered and disposed at each corner and between the two vessels are elongated heaters vertically extending substantially the entire height of the treating vessel. The space defined by the walls of the two spaced vessels is filled with a heating liquid, preferably an oil. Heat from the heaters is transmitted to the heating liquid and is in turn transmitted to the walls of the treating vessel. From the side walls of the treating vessel the treating solution is uniformly heated. A temperature control means is located on the outside of the second vessel and has a temperature responsive element extending into the heating liquid, directly over one of the heaters, whereby any significant change in the temperature of the liquid is noticed by the control means. The control means is operatively connected to the heaters, thus providing means to maintain the temperature of the liquid constant.

The top of the coating vessel is open, having a lid which fits thereon. Attached to the lower surface of the lid is a rack to which the parts that are to be treated are secured. When the lid is placed on the treating apparatus, the aforementioned parts are suspended and completely submersed in the treating solution. The parts are thereby subjected to a treating solution having a uniform temperature, resulting in a more uniform and consistent treatment.

It is therefore an object of the present invention to provide a simple and inexpensive device by which parts may be treated, resulting in coatings which are of the proper thickness and are consistent and uniform throughout the entire surface of the part.

It is further an object of the present invention to eliminate hot spots in such treatment tanks, thereby assuring longer tank and solution life and more uniform coating. It is a still further object of the present inventionto provide simple and inexpensive means to be used in conjunction with treating apparatus to aid in the prevention of sludging within the tank and solution deterioration or breakdown.

An additional object is to provide simple and inexpensive means which will aid in the reduction of boiling of the coating solution which results in solution failure and produces poor coatings and shorter tank life.

Another object of the present invention is to provide means to be used in conjunction with treating apparatus whereby heat may be uniformly applied to the treating solution in said apparatus, and by which uniform temperature of the solution may be maintained throughout the process within relatively close tolerance.

An additional object of the present invention is to provide novel method and means for treatment apparatus whereby the apparatus and treatment solution are heated evenly and uniformly, said means being partially comprised of an outer or second vessel concentrically disposed in spaced relation to a treating vessel and containing in the space defined by the inner surface of the second vessel and the outer surfaces of the treating vessel, a heating liquid, which liquid is maintained at a uniform and con stant temperature by means of elongated heaters disposed in this space existing between the two vessels.

Another object is to provide means to control the application of the heat to the treating vessel and solution, thereby preventing overheating or too rapid buildup of heat, thus eliminating hot spots.

Other and further objects, features and advantages will be apparent from the following description of a presently preferred embodiment of the invention, given for the purpose of disclosure, and taken in conjunction with the accompanying drawings, wherein like character references designate like parts throughout the several views and where:

FIGURE 1 is a perspective view of the preferred embodiment of the coating apparatus with the lid removed and with one corner of the treating apparatus broken away for purposes of illustration.

FIGURE 2 is a side view partially in section taken along lines 2-2 of FIGURE 1 but with the lid in its closed position, one corner of the coating tank being broken away for purposes of illustration, and

FIGURE 3 is a bottom view of the coating apparatus of FIGURE 1.

For purposes of illustration, the present invention will be described as utilized in a coating process which employs manganese phosphate in solution to act upon the objects being coated and which uses oil as its heating liquid. The manganese phosphate can be purchased under the tradename Acme Lubrite 97 and is mixed with 100 parts water to every 7 to 10 parts manganese phosphate for the treating herein set forth. This solution must be maintained within the temperature range of ZOO-210 F.

The treating solution first etches into the exposed surface of the aforementioned objects and then deposits manganese phosphate crystals into the metal. The crystals aid in the attracting and adhering of lubricants to the objects so treated, thereby providing better lubrication of these objects during their operation. Unless this treatment is uniform throughout all of the surface of the device, the object will not be uniformly lubricated when in operation. Treatment by a solution that is not evenly heated will result in such non-uniformity. Furthermore, an uneven application of heat to the treatment vessel will cause hot spots. The manganese phosphate is attracted to these hot spots resulting in sludging or a fairly rapid flaking out of manganese phosphate deposits which cause deterioration of the treating solution and decreases the treating vessel life.

Turning now to the figures of the drawings, the preferred embodiment of the present invention utilizes a fourcornered inner tank or vessel 10 concentrically disposed within and in spaced relation to an outer vessel generally, indicated by the numeral 12, which is also four-cornered. The outer tank 12 is composed of an exterior side wall 14, an interior side wall 16 and a bottom 20. Lying between the walls 14 and 16 is insulating material 18 which may be composed of glass wool or any other suitable substance.

The inner tank 10 is positioned within the outer tank 12, as is best shown in FIGURE 2, with its bottom 34 resting on bottom 20 of the outer vessel. It is maintained in this position by the connecting and supporting elements 22 which connect the two tanks at their uppermost edges. Members 22 also serve to seal off the space 30 which is defined by the interior walls 16, bottom member 20 and the exterior surfaces of the inner tank 10. Preferably, the vessel 10 is releasably secured in vessel 12 so as that it may be removed for repair and replacement purposes. Located within the space 30 is the heating oil 32 which may consist of any type of heating oil suitable for the temperature ranges that are to be used. The heating oil 32 surrounds the inner vessel 10 on all sides except on the bottom. An air space 33 is provided at the top of the chamber 30 to allow expansion of the heating oil 32 during heating. The lid generallyindicated by the numeral 36 is preferably of single wall construction, for reasons of economy although the lid shown in FIGURE 2 is of double walled construction to provide space for insulating material 38. Attached to the lid and extending downwardly from the lower surface thereof is a rack generally indicated as 42. The rack 42 is secured to the lid 36 by the nut and bolt members 44 or by any other suitable means such as welding. The rack 42 that is shown in the drawing is of the type used with cam shafts, although it may be shaped to any desired configuration depending upon the parts to be treated. Also located on the lid is an eylet member 46 which is used to lift the lid off of, or place the lid onto, the container.

Referring now to the heating apparatus employed in the present invention, a heating control mechanism 48 is located on an outer surface of the outer vessel 12. Extending from this control mechanism is a lead 52 which connects the heating system with an electrical power source (not shown). A thermostat 50 is connected by the conduit 54 to the control mechanism 48. A heat sensitive portion 56 of the thermostat 50 extends into the space 30 and is located directly above one of the heating elements '60 as will hereinafter be described. The heat responsive element 56 is located in the space 30 rather than the inner vessel itself to prevent any action of the treating solution on the heat responsive element itself, which would, of course, render the heat responsive element 56 less accurate. Furthermore, the present location of the element 56 provides a more accurate control as will be explained. The control mechanism 48 is operatively connected to the various heaters 60 by the conduit 58, the distribution member 62 and the four conduits 64 which lead to the bases 66 of the heating elements 60, which bases are fastened onto the bottom 2Q of the vessel 12.

The heating members themselves are standing U-shaped elements which extend approximately two-thirds of the distance from the bottom 20 of the outer vessel 12 to the uppermost edge of the inner vessel 10. The control mechanism 48 is partially comprised of means by which the electric current may be shut off or turned on in response to temperature changes of the heating oil 32 which are monitored by the thermostat 50.

In operation, the power source (not shown) is turned on and current is allowed to flow to the heating elements 60. The heat from the elements 60 is spread by conduction and convection to the heating oil 32 and in turn to the wall surfaces only of the inner vessel 10. Heat is transmitted from the walls of the inner vessel 10 to the treating solution itself. It has been found that heat applied to the bottom of the treating vessel will cause the treating substance to flake out and create sludging even more readily. Accordingly, the bottom 34 of the treating vessel 10 rests on the bottom 20 of the outer vessel, preventing the heating liquid 32 from flowing between the two bottoms whereby heat application to the solution from the bottom 34 is prevented.

Due to the use of the heating oil and to the location In the corners and to the shape of the heating elements 61?, heat is spread primarily by conduction and convection with relatively little radiation. The heat sensitive element 56 is located directly above one heating element 60, whereby it is more sensitive to the temperatures in and around the heating element 60. When the temperature reaches a predetermined level, the thermostat 50 operates to cut off the current flow to the heaters. This arrangement prevents any rapid buildup of heat in the corners of the vessels, thus eliminating to a great extent the poss bility of hot spots developing which would be more likely should the heat responsive element be located midway between two heating elements 60 for example. AC- cordingly, the heat buildup is relatively slow and uniform throughout. Once the desired temperature is reached, the

thermostat 50 functions to maintai n the tern er the desired level. p ature at The present arrangement of the heating elements 60' with respect to the treating vessel 10 provide a method and means by which the temperature of the heating solution may be more accurately controlled and may be maintamed more uniform throughout. This arrangement greatly cuts down on the radiant heat that would otherwise result, said radiation being a prime factor in improper heating. Due to the location of the thermostat, more accurate control can be maintained over the increase in temperature thereby preventing excessive buildup in temperature or the creation of hot spots.

As a result of the more uniform heat throughout the treating solution, the resulting treatment of the immersed objects is more uniform. Accordingly, the lubrication which is applied to the treated object during its operation will adhere better and longer to the object, thereby preventing galling. The elimination of the hot spots in the treating vessel itself will aid in the prevention of sludging and flaking crystalline deposits of phosphate although some sludging and flaking will occur in any such operation. As a result, breakdown or deterioration of the treating solution is prevented to a greater extent and the like of the treating vessel is also extended.

An additional advantage obtained by use of the present invention is that the uniform heating provided by the present arrangement eliminates the necessity of preheating the metal parts. Prior to the present invention, it was usually necessary to preheat parts before placing them in the vessel or the coolness of the parts themselves would disrupt the evenness of the solution temperature. The method of heating disclosed herein does away with this, while providing the same improved results. It is usually necessary, however, to extend the treatment period slightly, but the treatment results do not vary to any significant extent.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While the presently preferred embodiment of the invention is given for the purpose of disclosure, numerous changes in the detail of construction and combination, size, shape and arrangement of parts and uses may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. Apparatus for the treatment of metal parts includmg:

a treatment vessel having a bottom and sidewalls for receiving a treating solution, said vessel having a plurality of vertically extending corners in its sidewalls,

a second vessel surrounding the treatment vessel in spaced relation to the sidewalls thereof,

heating element means spaced in non-conducting relation between the second vessel and each vertically extending corner of the sidewalls of the treatment vessel,

a heating liquid in the space between the two vessels 4 whereby it surrounds only the sidewalls of the treatment vessel, and means for coacting with and regulating said heating element means such that the heat imparted to the heating liquid may be maintained continuously at a predetermined temperature.

2. The apparatus of claim 1 wherein, more particularly, the heating element means comprises elongate elements extending substantially parallel to the vertically extending corners in the sidewalls of the treatment vessel.

3. The apparatus of claim 2 wherein the treatment vessel has a top opening therein to receive metal parts and further including,

a removable lid to close said opening, and

rack means attached to said lid to which the metal parts may be secured for submersion in the solution when the lid is in its closed position.

4. The apparatus of claim 1 wherein, more particularly,

the heating liquid comprises a heating oil, and

the coacting means is further defined as including,

temperature responsive means located in said oil and in close proximity to one of said heating means, and

means operatively connected to said heating means for regulating, in response to temperature changes noticed by said temperature responsive means, the amount of heat produced by the heating means.

5. The apparatus of claim 1 wherein the heating element means has a connection for receiving power from a power source whereby said means may be heated.

References Cited UNITED STATES PATENTS 1,887,219 11/1932 Stranszky 99-419 2,427,146 9/1947 Lee 219-326 X 2,789,807 4/1957 Faler 266--6 X FOREIGN PATENTS 1,464,424 11/ 1966 France.

319,391 9/ 1929 Great Britain.

JOSEPH V. TRUHE, Primary Examiner C. L. ALBRITTON, Assistant Examiner U.S. Cl. X.R. 

